HomeHowTo › Creating an OS X Installation Partition

Creating an OS X Installation Partition

If you want to format your Mac’s hard drive to completely re-install OS X you usually need a DVD-ROM or a USB stick to install from. Another option is to create an extra partition on your hard drive to store the installer on so that you don’t need any external devices in order to re-install — this is the option that this post will be about. I’m not 100% sure if this works on all Macs, though.

1. Backup your important data.

2. Create an 8 GB partition for the OS X installer using the Disk Utility:

Create a partition for the OS X installer








3. Download the OS X Installer (in my case 10.9 Mavericks) from the App Store.

4. Open the Terminal and enter the following command to copy the installer (which is usually downloaded to the Applications folder) onto your new partition. You can also copy it onto a USB stick with this command. This might not work with earlier versions of OS X.

5. If you want to re-install your system, reboot it and hold [cmd]+[R] to start the Recovery System. If everything works, your Mac should boot into the 10.9 Mavericks installer. From here you can format your main partition and then install OS X to it.

6. After installation: to prevent the installer partition from being auto-mounted, first determine the partition’s UUID:

7. Then create the file /etc/fstab with the following content:



Leave a Comment